This invention relates to battery charging, and more particularly to a managed profile and facilitated programming of battery discharging and recharging so as to extend useful lifetimes and maintain service capacities of batteries which tend to develop undesirable "memory" characteristics.
Various types of batteries require differing profiles of battery charging/discharging if they are to provide dependable service and optimum service life. For example, lead-acid batteries commonly employed in automobiles retain optimal service life and characteristics best when maintained essentially fully charged. Such batteries suffer degradation and service life characteristics when they are subjected to deep discharge. Conversely, other types of rechargeable batteries tend to maintain optimal characteristics only if during each charge/discharge cycle they are deeply discharged. Examples of such batteries are those of the popular nickel cadmium variety.
Nickel cadmium batteries, if recharged after only partial discharge, tend to experience deterioration in their total charging capability. Thus, after several such cycles, a nickel cadmium battery will typically retain substantially less than its originally rated number of ampere hours, a result that is generally considered to be disadvantageous and to be avoided when practicable. However, it has been the practice in the past for battery users to oftentimes substitute a fresh battery for one which has had some use prior to full discharge so as to avoid experiencing complete loss of battery power during an extended period of use, thereby introducing the danger of adversely impacting subsequent battery characteristics of the only partially discharged battery.
To overcome the potentially deleterious results of repeatedly recharging batteries such as nickel cadmium batteries after only partial discharge, prior art proposals include the intentional deep discharge of any charge remaining in the battery as part of the recharging process. Illustrative of such a procedure are the proposals of U.S. Pat. Nos. 4,179,648, granted to Edward Samsioe on Dec. 18, 1979, and 4,302,714 to Sheldon Yefsky on Nov. 24, 1981.
Although these proposals were directed generally to the solution of the aforementioned problems, there still existed the matter of setting discharge and recharging conditions to tailor them to optimum levels for any of a variety of battery sizes and current ratings. One proposal includes the tailored conditioning of the equipment parameters to reflect the specific characteristics of a battery by providing for the manual setting of dip switches. However, such have been subject to the undesirable consequences of setting errors, switch malfunction, or loss of instructions for switch setting.
As well as nickel cadmium batteries, other batteries such as metal hydride batteries are currently being developed. There exists a need for a conditioning system which not only recognizes various sizes and current ratings of certain batteries, but also recognizes and conditions batteries of different compositions.